TY - JOUR
T1 - The effects of melanocortin peptides and corticosterone on habituation in the Great Plains toad, Bufo cognatus
AU - Carpenter, Anne M.
AU - Carr, James A.
N1 - Funding Information:
This work was performed in partial ful®llment for the Master of Science degree (A.M.C.). Thanks to Dr. Burns and Dr. Collie for helpful comments on earlier drafts of the manuscript. We also thank Kim Gregg and Zarqua Shahnaz for technical help and Pam Roberson for secretarial assistance. This work was supported in part by a grant from the Texas Tech University Research Enhancement Fund.
PY - 1996/9
Y1 - 1996/9
N2 - We investigated the ability of various melanocortin peptides and corticosterone to influence habituation of prey-catching behavior in the toad, Bufo cognates. Male toads were injected with various melanocortin peptide fragments or corticosterone 30 min prior to acquisition. Adrenocorticotropin (ACTH[1-39]), ACTH[4-10], and N-acetyl ACTH[1-13] amide (α-MSH) significantly decreased the number of turning reactions during acquisition in relation to controls. The effects of the noncorticotropic ACTH fragments were rapid and transient, occurring within the first 20 min of acquisition. Corticosterone caused a slight but significant decrease in the number of turning reactions. Neither des-acetyl α-MSH nor (Nle4, D-Phe7) α-MSH had any effect on acquisition. ACTH[1-39] was the only peptide that delayed extinction. The ability of α-MSH to facilitate acquisition was not observed in the presence of the α-MSH antagonist U-76188E. These data suggest that the effects of ACTH on habituation are, in part, independent of effects on glucocorticoid secretion. Apparently, similar structural requirements are necessary for the behavioral effects of melanocortins in amphibians and mammals.
AB - We investigated the ability of various melanocortin peptides and corticosterone to influence habituation of prey-catching behavior in the toad, Bufo cognates. Male toads were injected with various melanocortin peptide fragments or corticosterone 30 min prior to acquisition. Adrenocorticotropin (ACTH[1-39]), ACTH[4-10], and N-acetyl ACTH[1-13] amide (α-MSH) significantly decreased the number of turning reactions during acquisition in relation to controls. The effects of the noncorticotropic ACTH fragments were rapid and transient, occurring within the first 20 min of acquisition. Corticosterone caused a slight but significant decrease in the number of turning reactions. Neither des-acetyl α-MSH nor (Nle4, D-Phe7) α-MSH had any effect on acquisition. ACTH[1-39] was the only peptide that delayed extinction. The ability of α-MSH to facilitate acquisition was not observed in the presence of the α-MSH antagonist U-76188E. These data suggest that the effects of ACTH on habituation are, in part, independent of effects on glucocorticoid secretion. Apparently, similar structural requirements are necessary for the behavioral effects of melanocortins in amphibians and mammals.
UR - http://www.scopus.com/inward/record.url?scp=0030250350&partnerID=8YFLogxK
U2 - 10.1006/hbeh.1996.0028
DO - 10.1006/hbeh.1996.0028
M3 - Article
C2 - 8918679
AN - SCOPUS:0030250350
SN - 0018-506X
VL - 30
SP - 236
EP - 243
JO - Hormones and Behavior
JF - Hormones and Behavior
IS - 3
ER -